This test measures Cancer Antigen 19-9, a protein produced by cells in the pancreas, bile ducts, and gastrointestinal tract.
Diagnostic Value: Elevated CA 19-9 levels are commonly associated with pancreatic, gallbladder, or colorectal cancers, though mild increases can occur in benign biliary or liver disease.
Clinical Significance: It is widely used to monitor response to cancer therapy and detect recurrence after treatment.
Symptom Correlation: Patients may report abdominal pain, jaundice, nausea, or unexplained weight loss.
Because of its sensitivity to pancreatic and GI malignancies, CA 19-9 serves as an essential tool for monitoring gastrointestinal cancer activity.